6901d286fe
The 2.3 additions could be perceived as a memory leak so a note in the upgrading document could be helpful.
63 lines
1.8 KiB
Markdown
63 lines
1.8 KiB
Markdown
# Upgrading MariaDB MaxScale from 2.2 to 2.3
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This document describes possible issues when upgrading MariaDB
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MaxScale from version 2.2 to 2.3.
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For more information about MariaDB MaxScale 2.3, please refer
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to the [ChangeLog](../Changelog.md).
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Before starting the upgrade, we recommend you back up your current
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configuration file.
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## Increased Memory Use
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Starting with MaxScale 2.3.0 up to 40% of the memory can be used for
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caching parsed queries. The most noticeable change is that it improves
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performance in almost all cases where queries need to be parsed. Most of
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the time this happens when the readwritesplit router or filters are used.
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The amount of memory that MaxScale uses can be controlled with the
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`query_classifier_cache_size` parameter. For example, to limit the total
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memory to 1GB, add `query_classifier_cache_size=1G` to your
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configuration. To disable it, set the value to `0`.
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In addition to the aforementioned query classifier caching, the
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readwritesplit session command history is enabled by default in 2.3 but is
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limited to a maximum of 50 commands after which the history is
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disabled. This is unlikely to show in any metrics but it contributes to
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the increased memory foorprint of MaxScale.
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## Unknown Global Parameters
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All unknown parameters are now treated as errors. Check your configuration for
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errors if MaxScale fails to start after upgrading to 2.3.1.
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## `passwd` is deprecated
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In the configuration file, passwords for monitors and services should be
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specified using `password`; the support for the deprecated
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`passwd` will be removed in the future. That is, the following
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```
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[The-Service]
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type=service
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passwd=some-service-password
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...
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[The-Monitor]
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type=monitor
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passwd=some-monitor-password
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...
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```
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should be changed to
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```
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[The-Service]
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type=service
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password=some-service-password
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...
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[The-Monitor]
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type=monitor
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password=some-monitor-password
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...
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```
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